This is a follow on form the 'Steering Knuckle Needle Roller Bearing' how to
http://www.pajerouk.co.uk/forums/index.php/topic,14484.0.html as the inner bearing tends to take the needle roller bearing with it when it goes so best replaced together.
Parts required:
Bearing MB160662 £20.39 plus VAT
Dust Cover MB160948 £3.99 plus VAT
Follow the Needle Roller thread to stage 18 where you should have the ball joints split and steering knuckle removed as seen below

1. Proceed inboard to the flange with four bolts on the end of the driveshaft. Remove the 4 nuts and note which way the bolts go through from.
IMG]http://img.photobucket.com/albums/v130/TinyTim/bearings/tt017.jpg[/IMG]
2. Pull the driveshaft straight out towards you and set aside

The photo above is from underneath witth the driveshaft removed

3. Using a ball joint slpitting drift, lever the flange out from the car. The inner driveshaft and bearing are on the back of the flange and you have to vercome a circlip at the other end that fits in the differential's splines.

4. Remove bearing and dust cover - I used the ball joint splitting drift again.

5. Press on the new bearing and dust cover with a suitable drift - I used a section of copper tube

6. Check the circlip is in place, apply some grease to the splines and replace the inner shaft lining up the splines and pressing it into place to locate the circlip.
7. Re-assemble from step 19 of the needle roller thread.
not a difficult job although sometimes the inner shaft is very difficult to remove from the tube behind that flange as the bearing welds itself in.